Carl Powers was a schoolboy who died from botulinum poisoning whilst on a school trip to a London swimming pool. Initially ruled an accident at the time, his murder was solved by Sherlock after being directed towards the case by Jim Moriarty.[1]

Initially ruled to be an accident, the police ruled Carl's death to be drowning in a London pool. At the time, a young Sherlock thought the death was suspicious as his shoes were missing, and tried to get the police involved; however, his attempts went unnoticed.

The mystery of Carl's death was used by Moriarty as one of the puzzles Sherlock had to solve in order to save the life of an innocent person. Sherlock discovered that Carl died following the poisoning of eczema medicine through the introduction of botulinum.

Carl was a talented athlete who had a promising future in swimming. Moriarty justified his death with claims of bullying, although this was never substantiated. The care taken with his shoes – the discrepancy that first caught Sherlock's attention in 1989 – was almost obsessive, with the laces being changed four times in the single year he wore them, and the shoes being scrubbed and whitened in order to keep the shoes in a near-perfect condition.